Imaging lens and imaging apparatus equipped with the imaging lens

Abstract

An imaging lens is substantially constituted by five lenses, including: a first lens having a positive refractive power; a second lens having a negative refractive power; a third lens having a negative refractive power; a fourth lens having a negative refractive power; a fifth lens having a negative refractive power and an inflection point on the surface thereof toward the image side. All of the first lens through the fifth lens are single lenses, and the imaging lens satisfies predetermined conditional formulae.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a Continuation of PCT International Application No. PCT / JP2013 / 003251 filed on May 22, 2013, which claims priority under 35 U.S.C. §119(a) to Japanese Patent. Application No. 2012-117144 filed on May 23, 2012, U.S. Provisional Patent Application No. 61 / 660,001 filed on Jun. 15, 2012, and Japanese Patent Application No. 2013-097737 filed on May 7, 2013. Each of the above application(s) is hereby expressly incorporated by reference, in its entirety, into the present application.BACKGROUND OF THE INVENTION[0002]1. Technical Field[0003]The present invention is related to a fixed focus imaging lens for forming optical images of subjects onto an imaging element such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor). The present invention is also related to an imaging apparatus provided with the imaging lens that performs photography such as a digital still camera, a cellular telephone with...

AI Technical Summary

Benefits of technology

The present invention provides an imaging lens that can realize a wide angle of view and a short total length, which has a large image size and high imaging performance from a central angle of view to peripheral angles of view. This lens system can be produced at low cost without adhesive attachment steps and is suitable for use in imaging apparatuses such as cellular telephones, smart phones, and tablet terminals. The optical performance of the first and second imaging lenses of the present invention can be further improved by adopting a five-lens configuration with optimized lens elements and a large image size. The imaging apparatus of the present invention can obtain high resolution photographed images.

Problems solved by technology

However, the imaging lens disclosed in U.S. Patent Application Publication No. 20110181963 cannot obtain a sufficient maximum image height with respect to the total length of the lens.

Therefore, it is difficult for this imaging lens to be applied to an imaging element having a comparatively large image size that satisfies the demand for an increased number of pixels.

In the case that the entirety of the imaging lens disclosed in U.S. Patent Application Publication No. 20110181963 is proportionately enlarged to meet a desired image size, the total length of the lens will become excessively long, and shortening of the total length of the lens cannot be realized.

For this reason, the imaging lenses disclosed in U.S. Pat. No. 7,274,515 and Korean Patent Publication No. 10-2009-0055115 that satisfy the above power configuration incur cost for adhesive agents for adhesively attaching the cemented lenses together, and also involve adhesive attachment steps in addition to conventional production steps.

Therefore, it is difficult for these imaging lenses to be produced at low cost.

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